With the progress of display technology, displays have been developed in the trend of slimness and flexibility, and flexible displays (for example, foldable displays) have gradually become the next-generation displays. The flexible displays are made by flexible substrates in replacement of rigid substrates. The flexible substrates are characterized by bendability, ease of carriage, compliance with safety standards, and extensive applications in consumer products. However, the flexible substrates also have large coefficient of thermal expansion and poor resistance to heat, moisture, oxygen, and chemicals. A flexible substrate may serve to hold electronic devices and/or act as a cover, so as to perform a packaging process on the electronic devices. Since the flexible substrate may not completely block moisture infiltration and oxygen diffusion, the moisture infiltration and the oxygen diffusion may speed up the aging process of the environmental sensitive electronic devices on the flexible substrate. As a result, the lifetime of the environmental sensitive electronic devices is shortened.
A side wall barrier structure is employed according to the related art, so as to enhance the ability of the flexible display to block moisture and oxygen on edge seal. The side wall barrier structure is formed on the flexible substrate and is adhered to another flexible substrate by means of an adhesive, and thereby the ability of the flexible display with respect to the lateral resistance to water and oxygen may be further improved. In the event that the flexible display is in a bent state for a period of time, the side wall barrier structure may be deformed or even damaged, such that the moisture infiltration and oxygen diffusion into the flexible display may not be effectively prevented.